The probiotic strain was found to be as effective as a conventional antiseptic in reducing the occurrence of ventilator-associated pneumonia (VAP), a common complication in patients on breathing machines, according to findings published in the open-access journal Critical Care.​

VAP occurs when harmful bacteria from the mouth, throat or breathing tube are inhaled into the lungs.

"VAP is connected with longer intensive care and hospital stays, additional costs and high mortality. The risk of developing this condition increases by one per cent with each additional day of mechanical ventilation," ​explained lead researcher Bengt Klarin from the University Hospital in Lund, Sweden.

After randomising 50 patients to oral cleansing followed by washing with the antiseptic chlorhexidine CHX (0.1 per cent) or oral application of an emulsion of Lp299 (DSM 6595, 10 billion colony-forming units (CFU)), the researchers noted no difference between the groups.

" Based on the results of this pilot study, we conclude that the probiotic bacterium Lp299 constitutes a feasible and safe agent for oral care," ​

While most bacterial strains with health benefits focus on the gut, the use of Lp299 in the mouth also qualifies as being probiotic, according to the FAO/WHO definition as "live microorganisms which when administered in adequate amounts confer a health benefit on the host"​.

Added benefits​

L. plantarum​, found naturally in saliva and also in fermented food products like pickles and sauerkraut, may have additional benefits, suggested the authors. Most notable amongst these is a lack of contribution to the development of antibiotic-resistant strains.

"As the bacteria adhere to the oral mucosa, they are able to counteract potentially pathogenic bacteria around the clock, which is superior to the fairly short-term effect of orally applied chemical agents," ​they said.

Moreover, no side effects were noted in the probiotic group. On the other hand, common side effects associated with oral CHX use include tooth discolouration, irritation and, very occasionally, serious allergic reactions, they said.

"Clearly, it is also important to point out that the findings of this pilot study must be interpreted with great caution, and the trends indicated by the data must and will be further examined in a larger investigation," ​wrote the authors.

"Nevertheless, our main objectives have been met, because we found that Lp299 did become established in the oral cavity, it had no apparent adverse effects and the results provide a basis for calculating the number of patients needed to test the trends observed in the planned definitive study."​